The invention relates to radio frequency (RF) feed horns such as can be used, for example, with reflector antenna systems. It can be advantageous to operate reflector antenna systems at two or more different frequency bands. For example, one frequency band can be for transmitting RF signals, and another frequency band can be for receiving RF signals. Current reflector antennas operating at two separated frequency bands generally produce an illumination pattern on the main reflector antenna that may differ in size by, for example, about fifty percent due to the frequency difference between the signals of the two frequency bands. This size difference may result in a decrease in efficiency at one or both frequency bands. Attempts to address this problem have included inserting a dielectric rod or other dielectric material into the horn. However, while the dielectric can ameliorate the illumination pattern problem to a certain extent, it may also limit the power handling capabilities of the horn. Accordingly, it would be beneficial to provide a horn that addresses illumination pattern efficiency, power handling challenges, and/or provides other benefits.